Liquid developer feed system for printing machines



F. H. FRANTZ Dec. 14, 1954 LIQUID DEVELOPER FEED SYSTEM FOR PRINTING MACHINES Filed Aug. 24, 1950 2 Sheets-Sheet 1 FIG.1

INVENTOR. FREDERICK H. FRA/VTZ F. H. FRANTZ Dec. 14, 1954 LIQUID DEVELOPER FEED SYSTEM FOR PRINTING MACHINES 2 Sheets-Sheet 2 Filed Aug. 24, 1950 FIG. 3

l N V E N TO R FEEDER/CK H. FAA N 7'2 ATT United States Patent LIQUID DEVELOPER FEED SYSTEM FOR. PRINTING MACHINES Frederick H. Frantz, Binghamton', N. Y., assignor to Gencral Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application August 24, 195i), Serial No. 181,192 1 Claim. (Cl. 9589) This invention relates to photo-printing apparatus of the type utilizing a volatile liquid developer, and more specifically to an arrangement of the developer liquid circulating system thereof.

Dry process photo-printing apparatus for diazo coated sensitized material generally employs ammonia vapor for development of the exposed print. The developer is stored in the form of aqueous ammonia which is heated in a vaporizing developing tank and the sensitized material, in contact with the tank, is subjected to the vapors.

Printing machines of this type are generally of compact structure incorporating, aside from the developing instrumentalities, a light source, print and original feed, as well as separating and stacking mechanisms. The various component elements of the machine are arranged in a housing which forms a complete enclosure. Within this enclosure there is provided room for a storage container for the ammonia liquid and a circulatory system for feeding the liquid to the developing tank. The amount of liquid to be fed into the tank depends on various factors, such as the type of sensitized material, the speed of the machine etc. The feed can be regulated by the operator by means of an ammonia feed control having an adjustment knob extending from the housing.

It is advantageous for the operator of the machine to know, at all times, whether the developing liquid circi'ilating system is in proper operation, and that the adjustment of the rate of delivery is maintained. Accordingly, it is a particular feature of this invention that the circulatory system is so arranged that the function thereof is visible to the operator at all times.

It is also an object of the invention to provide an improved liquid feed by a particular arrangement of the component elements of the circulatory system, in which certain parts are placed in a supervisory position visible to the operator of the machine.

A further object of the invention is to improve the circulatory system by providing a forced, primary unidirectional liquid flow, and a secondary controllable gravity feed flow into the developing tank.

Other features and objects will be apparent from the following description of the invention, pointed out in particularity in the appended claim, and taken in connection with the accompanying drawing, in which:

Figure l is a side elevational view of the printing machine with the side of the housing removed showing the arrangement of parts of the circulatory system;

Figure 2 is a perspective view of the machine with portions of the housing cut oil, showing the relative placement of the component elements forming the developing liquid feed;

Figure 3 is a schematic representation of the developing liquid circulatory and feed system.

Essentially, the invention contemplates a developing liquid circulatory and feed system, of which the component parts are enclosed in the housing of the printing machine, except for certain of these which are placed in a supervisory position extending from the housing, or located behind a suitable opening in the housing for continuous observation of the proper function thereof.

Only such portions of the apparatus are shown in the drawings in detail which pertain to the circulatory system. The remaining components, located within the housing, are not indicated, except those parts which form a housing or extend therefrom.

Referring to Figures 1 and 2, it is seen that the housing 4 of the machine forms a complete enclosure for all the operating parts. A feed board 5 extends from the front or the machine upon which the original is placed when a print is to be made, together with the sensitized sheet material. Moving. tapes or other suitable instrumentalities, not shown here, convey the original and the sensitized paper into the machine and past a light source for transradiation. Thereafter, the original is separatedfrom the copy and deposited in the original receiving tray 6. Meanwhile, the copy, i. e., the exposed sensitized paper, is guided past the developing tank 5. The latter is supplied with aqueous ammonia in a particular manner as hereinafter described. The ammonia is vaporized in the tank by suitable heating means. hot this reason, the developing tank 8 is termed a tank. '1 he sensitized paper in-contact With the developing tank 8 is sub ected to the vapors generated. 'lhe latent image is thus developed while the sensitized paper passes the developing tank, arriving, thereafter, as the linished print at the print receiving tray 9.

The lever 10, conveniently located for the operator, serves to control the speed of the machine. Near this lever, and in full view of the operator, are located the controls and indicators of the ammonia feed system.

As seen in JIIgLlICS l and 2, the developer liquid feed apparatus is located at the side of the machine. The PaI'LS thereof are, of course, covered fully by the wall of the housing 4 which is cut away in the figures for the purpose or iilUSUaLlOIl. Reference should also be had to rigure 3 which gives the schematic representation of the circulatory system.

Essentially, the liquid distribution comprises a forced unidirectional circulatory portion and a gravity feed portion. the first-mentioned portion includes the ammonia supply container 11, the pump 13 and the overflow glass 14. Conduit 1:5 interconnects the container 11 with the inlet of the pump 13. A check valve 16 is placed between the outlet 1/ or the container 11 to prevent back flow of the liquid when the pump 16 is idle. in this manner, the residual liquid in the system is prevented from returning through the idle pump into the container, which would require the priming of the pump at every start. The conduit 16 connects the outlet or the pump 13 with the inlet of the overflow glass 14, and the conduit 12 conveys the return from the overflow outlet 29 to the inlet of the container 11.

The gravity feed portion comprises the overflow glass 14 and the valve 19, the drip sight glass 21, and the vaporizer developing tank 8. Conduits between these points complete the feed. Of these, conduit 22 may be flexible so as to be compressed by a simple clamp which functions as the valve 19. A knob 23 pro ects outside from the housing 4 for the manual EldjllSLlIlfiDt of the gravity teed. 'lhe condensate of the ammonia vapor in the tank 8 is removed by conduit 25 into a waste container 26.

A better view can be had of the developer liquid feed and circulatory system from Figure 3. It will be observed that the overflow glass 14 has an inlet 27 and outlet 28 at approximately the same level, an overflow outlet 29 at a higher level, and an air inlet 36 at a level above the overflow outlet 29. The pump 13 may be of any suitable type. A centrifugal pump is shown here for the sake of illustration. 'lhe check valve 16, as mentioned before, assures a unidirectional flow and in operation there is a continuous circulation in the forced circulatory portion through conduits 18 and 12, so that in the overflow glass 14 a liquid level is maintained at the height of the overflow outlet 29. The tank supply is taken from the liquid reserve in the overflow glass by the gravity feed through the conduit 22. The rate of flow, generally in consecutive drip form, is controlled by the valve 19 by adjusting the knob 23, and can be observed in the drip sight glass 21.

The overflow glass 14, as well as the drip sight glass 21, are mounted in a supervisory position so that the operator can, at all times, observe the function of both the forced circulatory system and the rate of liquid delivery to the tank 8. This is of prime importance, for any change in the liquid level below that of the overflow outlet 29 indicates either an insufiicient amount of liquid in the container 11, or a defect in the operation of the vaporizing developing.

3 machine. Constant and easily accessible observation of the rate of fi'ow through the drip sight glass 21 is important for adjusting the feed to the developing tank in accordance with the printing speed of the machine and the type of sensitized material.

I claim:

In aphotographic printing apparatus utilizing a volatile liquid developing medium, a housing enclosing the component parts of said apparatus, said parts including a liquid supply container, an evaporator developing tank, a circulatory system for said liquid comprising a forced unidirectional primary circulatory portion consisting of an overflow glass having an inlet and a supply outlet at substantial equal level, an overflow outlet at a level higher than said inlet, an air vent at a level higher than said overflow outlet, a pump, and interconnecting conduits, and an intermittent gravity feed portion including said supply outlet, a drip sight glass, 21 flexible conduit between said overflow glass and said drip sight glass, a valve having an adjustment knob for compressing said flexible conduit thereby controlling the rate of flow in said last-named portion, said knob and a portion of said overflow glass extending from said housing, and said drip sight glass being mounted behind an opening in said housing in close proximity to said knob and said overflow glass for separate visible indication of the function of both said circulatory portions and for control of said gravity feed portion.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,927,886 Burns Sept. 26, 1933 2,096,015 Von Meister et a1 Oct. 19, 1937 2,200,996 Reed May 14, 1940 2,384,155 Brunk Sept. 4, 1945 

